Figure 6.

Ag-specific multifunctional T cell responses in plant-produced G-Ag85A- and bacteria-produced NG-Ag85A-immunized mice in the early phase of Mtb HN878 infection. Four weeks postinfection, the mice from each group were euthanized, and their lung cells (1 × 10⁶ cells) were restimulated ex vivo with NG-Ag85A or G-Ag85A (2.5 μg/mL). The percentages of Ag-specific CD4⁺CD62L^loCD44^hi and CD8⁺CD62L^loCD44^hi T cells producing IFN-γ, TNF-α, and/or IL-2 among the cells isolated from the lungs of each group of mice were analyzed via flow cytometry by gating the cells into CD4⁺ (a) and CD8⁺ (b) T cells. The data are presented as the means ± SDs from 5–6 mice in each group. One-way ANOVA was used to determine the significance of the differences. * p < 0.05, ** p < 0.01, and *** p < 0.001. (c) The mean frequencies of cells coexpressing IFN-γ, TNF-α, and/or IL-2 are shown in the pie charts. The arcs around the pie charts indicate the percentage of T cells that produced multiple cytokines. Unpaired t-tests were used to determine the significance of the differences in the percentage of polyfunctional T cells between the G-Ag85A- and NG-Ag85A-immunized groups.